Antenna system having an automatically adjustable directional antenna structure and method for automatically adjusting a directional antenna structure

Abstract

An antenna system having an automatically adjustable directional antenna structure and a method for automatically adjusting a direction antenna structure are disclosed. The method includes receiving a first radiation signal, delaying the first radiation signal to obtain a first delay signal, receiving a second radiation signal, delaying the second radiation signal to obtain a second delay signal, combining the first delay signal and the second radiation signal to obtain a first combined signal, combining the first radiation signal and the second delay signal to obtain a second combined signal, detecting the power of the first combined signal to output a first amplitude, detecting the power of the second combined signal to output a second amplitude, and rotating a substrate based on the first amplitude and the second amplitude, so that a normal direction of the substrate is rotated and substantially aimed at an object.

What is claimed is: 
     
         1 . A method for automatically adjusting a directional antenna structure, for tracing a flying object, wherein the directional antenna structure comprises a substrate, a first antenna, and a second antenna, the first antenna and the second antenna are assembled on the substrate, wherein the method comprises:
 receiving a first radiation signal via the first antenna;   delaying the first radiation signal to obtain a first delay signal;   receiving a second radiation signal via the second antenna;   delaying the second radiation signal to obtain a second delay signal;   combining the first delay signal and the second radiation signal to obtain a first combined signal;   combining the first radiation signal and the second delay signal to obtain a second combined signal;   detecting the power of the first combined signal to output a first amplitude;   detecting the power of the second combined signal to output a second amplitude; and   rotating the substrate based on the first amplitude and the second amplitude, so that a normal direction of the substrate is rotated and substantially aimed at the object.   
     
     
         2 . The method according to  claim 1 , wherein the step of “rotating the substrate based on the first amplitude and the second amplitude” comprises:
 outputting a control signal based on the first amplitude and the second amplitude; and 
 driving a rotating mechanism based on the control signal so as to rotate the substrate. 
 
     
     
         3 . The method according to  claim 1 , wherein the step of “rotating the substrate based on the first amplitude and the second amplitude” comprises:
 comparing the first amplitude with the second amplitude; 
 wherein the normal direction of the substrate is rotated toward the incidence direction of the first radiation signal when the first amplitude is greater than the second amplitude; 
 the normal direction of the substrate is rotated toward the incidence direction of the second radiation signal when the first amplitude is less than the second amplitude; and the substrate is stopped rotating when the first amplitude is equal to the second amplitude. 
 
     
     
         4 . The method according to  claim 1 , wherein the step of “rotating the substrate based on the first amplitude and the second amplitude” comprises:
 obtaining a difference between the second amplitude and the first amplitude to output a difference value; 
 comparing the difference value with a threshold value; 
 wherein the normal direction of the substrate is rotated toward the incidence direction of the first radiation signal when the difference value is greater than the threshold value; the normal direction of the substrate is rotated toward the incidence direction of the second radiation signal when the difference value is less than the threshold value; and the substrate is stopped rotating when the difference value is equal to the threshold value. 
 
     
     
         5 . The method according to  claim 1 , wherein the directional antenna structure further comprises a third antenna and a fourth antenna, and the first antenna, the second antenna, the third antenna, and the fourth antenna are collectively formed as a rectangular array on the substrate, and the method further comprises:
 receiving a third radiation signal via the third antenna;   delaying the third radiation signal to obtain a third delay signal;   receiving a fourth radiation signal via the fourth antenna;   delaying the fourth radiation signal to obtain a fourth delay signal;   combining the third delay signal and the fourth radiation signal to obtain a third combined signal;   combining the third radiation signal and the fourth delay signal to obtain a fourth combined signal;   detecting the power of the third combined signal to output a third amplitude; and   detecting the power of the fourth combined signal to output a fourth amplitude.   
     
     
         6 . The method according to  claim 5 , further comprising:
 adding the third amplitude and the first amplitude to output a first added amplitude;   adding the fourth amplitude and the second amplitude to output a second added amplitude; and   rotating the substrate based on the first added amplitude and the second added amplitude.   
     
     
         7 . An antenna system having an automatically adjustable directional antenna structure, wherein the system is adapted for tracing a flying object, and the system comprises:
 a substrate;   a first antenna for receiving a first radiation signal;   a second antenna for receiving a second radiation signal, wherein the first antenna and the second antenna are assembled on the substrate;   a rotating mechanism coupled to the substrate;   a first delay line coupled to the first antenna and for delaying the first radiation signal to obtain a first delay signal;   a second delay line coupled to the second antenna and for delaying the second radiation signal to obtain a second delay signal;   a first division module for combining the first delay signal and the second radiation signal to obtain a first combined signal and combining the first radiation signal and the second delay signal to obtain a second combined signal;   a power detecting module for detecting the power of the first combined signal to output a first amplitude and detecting the power of the second combined signal to output a second amplitude; and   a control module coupled to the rotating mechanism and the first division module, wherein the control module is adapted to control the rotating mechanism based on the first amplitude and the second amplitude so as to rotate a normal direction of the substrate to substantially aim at the object.   
     
     
         8 . The antenna system according to  claim 7 , wherein the control module comprises:
 a comparator for comparing the first amplitude and the second amplitude to output a control signal;   wherein the normal direction of the substrate is rotated toward the incidence direction of the first radiation signal when the first amplitude is greater than the second amplitude; the normal direction of the substrate is rotated toward the incidence direction of the second radiation signal when the first amplitude is less than the second amplitude; and the substrate is stopped rotating when the first amplitude is equal to the second amplitude.   
     
     
         9 . The antenna system according to  claim 7 , wherein the control module comprises:
 a subtractor for obtaining a difference between the second amplitude and the first amplitude to output a difference value; and   a comparator for comparing the difference value with a threshold value to output a control signal;   wherein the normal direction of the substrate is rotated toward the incidence direction of the first radiation signal when the first amplitude is greater than the second amplitude; the normal direction of the substrate is rotated toward the incidence direction of the second radiation signal when the first amplitude is less than the second amplitude; and the substrate is stopped rotating when the first amplitude is equal to the second amplitude.   
     
     
         10 . The antenna system according to  claim 7 , further comprising:
 a third antenna for receiving a third radiation signal;   a fourth antenna for receiving a fourth radiation signal, wherein the first antenna, the second antenna, the third antenna, and the fourth antenna are collectively formed as a rectangular array on the substrate;   a third delay line coupled to the third antenna and for delaying the third radiation signal to obtain a third delay signal;   a fourth delay line coupled to the fourth antenna and for delaying the fourth radiation signal to obtain a fourth delay signal; and   a second division module for combining the third delay signal and the fourth radiation signal to obtain a third combined signal and for combining the third radiation signal and the fourth delay signal to obtain a fourth combined signal, wherein the power detecting module is further provided for detecting the power of the third combined signal to output a third amplitude and detecting the power of the fourth combined signal to output a fourth amplitude, and the control module comprises:   a first adding circuit for adding the third amplitude and the first amplitude to output a first added amplitude and adding the fourth amplitude and the second amplitude to output a second added amplitude; and   a control unit for generating a control signal to the rotating mechanism based on the first added amplitude and the second added amplitude.   
     
     
         11 . The antenna system according to  claim 10 , further comprising:
 a third division module for combining the first radiation signal and the third delay signal to obtain a fifth combined signal and combining the first delay signal and the third radiation signal to obtain a sixth combined signal; and   a fourth division module for combining the second radiation signal and the fourth delay signal to obtain a seventh combined signal, and combining the second delay signal and the fourth radiation signal to obtain an eighth combined signal, wherein the power detecting module is further provided for detecting the power of the fifth combined signal to output a fifth amplitude, detecting the power of the sixth combined signal to output a sixth amplitude, detecting the power of the seventh combined signal to output a seventh amplitude, and detecting the power of the eighth combined signal to output an eighth amplitude, and the control module further comprises:   a second adding circuit for adding the seventh amplitude and the fifth amplitude to output a third added amplitude and adding the eighth amplitude and the sixth amplitude to output a fourth added amplitude; the control unit is further provided for generating another control signal to the rotating mechanism based on the third added amplitude and the fourth added amplitude, and the rotating mechanism rotates the substrate based on the another control signal so that the normal direction of the substrate is rotated and substantially aimed at the object.